Allow redux 4.

package.json

@@ -20,7 +20,7 @@
   "author": "Herbert Vojčík <herby@mailbox.sk>",
   "license": "MIT",
   "dependencies": {
-    "redux": "^3.7.2",
+    "redux": "^3.7.2 || ^4.0.0",
     "redux-effex": "^1.1.2",
     "redux-sac": ">=0.6.0 <0.9.0"
   }